1. Field of the Invention
The invention relates to locking structure capable of preventing the opening of relatively slidable doors such as glass patio doors and the like. The invention further includes structure capable of preventing the lifting out of such doors from associated tracks within which the doors move.
2. Description of the Prior Art
Building practices over the last thirty or more years have often included sliding glass doors and large area sliding glass windows as a means for allowing visual and actual communications between the interior of a home and the out of doors. Such closures typically constitute two glass doors, one of which is stationary or fixed, and the other of which is slidable in a horizontal sense upon a track which is typically formed of metal. Both doors or closures typically fit within this track. In some situations, both of the doors are movable within the track. Latching or locking mechanisms usually supplied with such closures have unfortunately been subject to easy defeat by persons attempting to gain unauthorized entry into the home. Accordingly, forced entry through such closures is commonplace and constitutes the most usual mode of unauthorized entry into those housing structures fitted with such closures. Various supplementary locking and latching structures have been provided in the art for improving the security of such sliding closures, U.S. Pat. No. 926,460 to Benedict describes one such example of a locking structure for sliding doors, the structure including two relatively hinged members, one of which is attached to either a door or stationary framing structure while the other member pivots into a recess formed in a sliding door to prevent movement of the door. Voigt, in U.S. Pat. No. 1,112,738 provides a locking device for sliding doors in which a locking element disposed on the vertical edge surface of one of the doors extends into a recess formed in the other door to secure the doors. Hughes, in U.S. Pat. No. 2,759,748, discloses a sash fastener for windows wherein one element pivotally mounted on one of the windows is movable into an interengaging relationship with a stationary locking element mounted on a second window or on stationary window framing structure. In U.S. Pat. No. 2,818,919, Sylvan discloses a window locking structure having locking elements which can be moved into a cooperating relationship which prevents movement of the window frames. Grossman, in U.S. Pat. No. 2,941,832, provides a sliding door lock wherein a pivotable element mounted on one of the doors can be rotated into a recess formed in the adjacent sliding door or stationary framing structure. More recently, Silk, in U.S. Pat. No. 3,378,293, describes blocking elements for sliding closures wherein a hinged member mounted to the floor along track elements has a portion which pivots into blocking relation with a door movable within the track element. These and other prior art structures have met with varying degrees of success. Disadvantages of certain of the locking systems include the necessity for forming special recesses and similar receptive structure in at least one of the doors or in framing structure. Certain other locking systems have been as easily defeatible as the usual locking mechanisms which are formed integrally with such sliding closures. Further, the prior art has not included within a simple, inexpensive, and relatively easily installable locking system a structural feature which would prevent the lifting of the doors from the associated tracks. In spite of the numerous prior devices intended to accomplish at least a portion of the objects accomplished according to the present invention, there remains a need in the art for a simple locking system which can be readily installed without the use of special tools and without the necessity for modifying the sliding closures.